Reword schema.org integration method

[jonoalderson]

The following JSON-LD (derived from a truncated Yoast SEO example; see https://developer.yoast.com/features/schema/specification/) is an example of an alternative implementation of wordproof into an existing schema.org graph structure.

It uses the following approach:

• It makes the encodedTimestamp a (custom) property of the main entity of the page (in this case, an Article), which contains the various wordproof properties.
• It adds a numeric version property to the main entity.
• It adds a (custom) revision property to the main entity, which contains an array of references-by-ID to previous versions of the main entity, each of which in turn has a version and encodedTimestamp property.

I recommend this approach specifically, because:

• The revisions are the explicit property of the main entity of the page (which may vary by context, e.g., a WebPage vs a NewsArticle)
• The relevant information about an entity can be inherited from a parent (e.g., it can be assumed that if a newer version doesn't declare an author property, that that property hasn't changed).
• If/when these standards are more broadly adopted, the syntax can be easily adjusted to deprecate the additionalProperty mechanism.

{
  "@context": "https://schema.org",
  "@graph": [
    {
      "@id": "https://www.example.com/blog/example-article/",
      "@type": "WebPage",
      "isPartOf": {
        "@id": "https://www.example.com/#/schema/website/abc123"
      },
      "name": "Example page name",
      "url": "https://www.example.com/blog/example-article/"
    },
    {
      "@id": "https://www.example.com/#/schema/website/abc123",
      "@type": "WebSite",
      "name": "Example website",
      "publisher": {
        "@id": "https://www.example.com/#/schema/organization/abc123"
      },
      "url": "https://www.example.com"
    },
    {
      "@id": "https://www.example.com/#/schema/person/abc123",
      "@type": "Person",
      "name": "Example person name"
    },
    {
      "@id": "https://www.example.com/#/schema/image/abc123",
      "@type": "ImageObject",
      "caption": "Example caption",
      "height": 250,
      "url": "https://www.example.com/uploads/example-image.jpg",
      "width": 250
    },
    {
      "@id": "https://www.example.com/#/schema/organization/abc123",
      "@type": "Organization",
      "logo": {
        "@id": "https://www.example.com/#/schema/image/abc123"
      },
      "name": "Example organization name",
      "url": "https://www.example.com/#/schema/organization/"
    },
    {
      "@id": "https://www.example.com/blog/example-article/#/schema/article/abc123",
      "@type": "Article",
      "additionalProperty": [
        {
          "@type": "PropertyValue",
          "name": "encodedTimestamp",
          "value": [
            {
              "@type": "PropertyValue",
              "name": "blockchain",
              "value": "eos"
            },
            {
              "@type": "PropertyValue",
              "name": "transactionId",
              "value": "77ac208d9a01d0cf40345786da28accd2795f5a6a6cf3692168a2a71ca165708"
            },
            {
              "@type": "PropertyValue",
              "name": "hash",
              "value": "8A258E516081C36B866812E49495628CBDC1DD4126DB321A28AE95EE55B83BAB"
            }
          ]
        },
        {
          "@type": "PropertyValue",
          "name": "revision",
          "value": [
            {
              "@id": "https://www.example.com/blog/example-article/#/schema/article/abc123|version=17"
            }
          ]
        }
      ],
      "articleSection": "Cats,Dogs,Recipes",
      "author": {
        "@id": "https://www.example.com/#/schema/person/abc123"
      },
      "commentCount": 6,
      "dateModified": "2019-07-10T08:43:03+00:00",
      "datePublished": "2019-07-10T08:08:40+00:00",
      "description": "Example article description",
      "headline": "Example article headline",
      "image": [
        {
          "@id": "https://www.example.com/#/schema/image/abc123"
        }
      ],
      "inLanguage": "en-US",
      "isPartOf": {
        "@id": "https://www.example.com/blog/example-article/"
      },
      "mainEntityOfPage": {
        "@id": "https://www.example.com/blog/example-article/"
      },
      "publisher": {
        "@id": "https://www.example.com/#/schema/organization/abc123"
      },
      "version": "18"
    },
    {
      "@id": "https://www.example.com/blog/example-article/#/schema/article/abc123|version=17",
      "@type": "Article",
      "additionalProperty": [
        {
          "@type": "PropertyValue",
          "name": "encodedTimestamp",
          "value": [
            {
              "@type": "PropertyValue",
              "name": "blockchain",
              "value": "eos"
            },
            {
              "@type": "PropertyValue",
              "name": "transactionId",
              "value": "a4ce94cc4c0adda8075ac133b4de884a282e3de4ee1734d808a2e9737e06f5a1"
            },
            {
              "@type": "PropertyValue",
              "name": "hash",
              "value": "2DAD3812C721EF4A21541CCF1DB7C54BA1643294162B038ACDE8CF1CE7DA511B"
            }
          ]
        }
      ],
      "author": {
        "@id": "https://www.example.com/#/schema/person/abc123"
      },
      "dateModified": "2019-05-10T08:08:40+00:00",
      "datePublished": "2019-05-10T08:08:40+00:00",
      "headline": "Previous title from version 17",
      "image": {
        "@id": "https://www.example.com/#/schema/image/abc123"
      },
      "mainEntityOfPage": {
        "@id": "https://www.example.com/blog/example-article/"
      },
      "publisher": {
        "@id": "https://www.example.com/#/schema/organization/abc123"
      },
      "url": "https://www.example.com/blog/example-article/?version=17",
      "version": "17"
    }
  ]
}